JPS6023759B2 - Safety device that automatically seals hydraulic pipelines in subsea well casings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Broadly speaking, the present invention is intended to operate a liquid-operated system, such as a leak prevention machine, in a seabed hole when the connection between a wellbore and an underwater standpipe becomes disconnected or damaged. Concerning safety layers to maintain condition.

More specifically, the present invention provides for connecting hydraulic conduits in subsea wellhead casings to wells to which the casing corresponds.
The present invention relates to a safety bag that automatically seals when removed from the head-connector and Christmas assembly to maintain hydraulic pressure activating the subsea borehole liner, ie, the leak prevention device. An example of an internal annular valve arrangement is the annular valve disclosed in Watki Ships US Pat. No. 3,36, French I8.

The Watki vessel's annular valve was very effective in sealing the annulus during routine maintenance and pre-planned production operations. However, having to use a wireline tool to actuate the annular valve
In the event of a break or damage to the casing string or casing head, there is no provision to automatically seal the annulus or hydraulic line and prevent fluid from escaping therefrom and contaminating the environment. . This problem is magnified in subsea operations because tidal movements cause the drilling platform or vessel to move, increasing the risk of separation at the casing head.
An important aspect of subsea operations is primarily the control of various leakage prevention devices at or below the casing head.

A particularly effective method for activating various types of leak-proof bag hawks has utilized pressurized hydraulic control lines to activate the safety device in the open and closed positions. In this case, the risk of contamination is so great that wireline tools should not be used to actuate the hydraulic line valves in case the hydraulic control system is damaged and the leak prevention device is not activated. It turned out to be inappropriate. The sea pressure control line of the subsea leakage prevention system shall be automatic. It is therefore an object of the present invention to provide an apparatus and method for automatically sealing hydraulic conduits within a subsea well casing when the casing is disengaged from a corresponding well head connector and Christmas tree assembly. and to provide a control device that can close the well if the Christmas tree assembly is inadvertently damaged or destroyed.

Broadly speaking, the safety device of the present invention consists of:
For example, it may include a valve arrangement mounted within the well casing head in conjunction with a hydraulic line leading to a leak prevention device. The valve assembly is moved to the line open position by seating the connector assembly on the water head. A device is provided to force the valving device into line closure & formation so that when the well head connector assembly is removed from the casing head, the valving device closes the line and presses the hydraulic line away from the surrounding seawater at the well head. and maintain the line pressure necessary to keep the subsea borehole (i.e., leak prevention device) operational. BRIEF DESCRIPTION OF THE DRAWINGS The invention can be understood from the following description of preferred embodiments, taken in conjunction with the accompanying drawings.

Referring first to FIG. 1, a submarine boring structure is shown. A bowling Christmas tree 1 has been lowered onto a bowling template 5 and guided into position by a guide cable 3 attached to the template 5 by a connector 3a. A guiding structure 4 at the base of the Christmas tree 1 serves to position the Christmas tree on the bowling template. Guide posts 2 project upwardly from each part of the Christmas tree 1 and are used to guide subsequent parts of the Christmas tree into position. This is done by engaging the guide socket 2a in the lower part of the Christmas tree when the trailing part of the tree is lowered into position. A well head having a lower body portion 10
Connector assembly 6 locks the Christmas tree to the top of well casing head 7 which extends upwardly through template 5. Hydraulic pressure control pipes 35a, 35 toward the hydraulic pressure device in the seabed hole, that is, the leakage prevention device (not shown)
b is adjusted by the insulating valve block 9.

As best seen in Figure 2, Christmas Tree 1
The lower portion 101 of the is connected to the body by conventional fasteners such as bolts 100 and is also connected to the well casing head 7 by a well head connector assembly 6.

The well head connector assembly 6 shown in FIG.
It has an upper body portion 10a and a lower body portion 10b which are interconnected by an interlocking joint generally indicated at 110.

As a result, the upper main body portion 10a functions as a protective cover. Lower body portion 10b is attached to lower portion 101 of Christmas tree 1 by known fastening means such as bolt assemblies 111. To attach the Christmas tree to the well casing head, use the Christmas
The tree and the head-well connector assembly attached thereto are lowered onto the well casing head 7, and the seating surface of the well casing head 7 is finally brought into contact with the abutting portion 17 of the lower body portion 10b. . at this point
A hydraulically actuated latch mechanism 11 whose dog 13 aligns with a coin recess 13a on the outer surface of the well casing head 7 and acts via a push rod 14 to push the camming block 12 into the coin position. By actuation, the dog can be locked in the position shown in FIG. When the camming block 12 rests on the dog 13, this dog is pushed into the locking recess 13a to secure the Christmas tree against the well casing head. A combination of seals is provided to prevent leakage of high pressure fluid between the well casing head 7 and the Christmas tree 1.

Seal element 15 provides a fluid tight seal between the outer surface of well casing head 6 and the inner surface of lower body portion 10b of the connector assembly. Furthermore, a seal 18 made of swageable metal is provided between the sealing surface 7a of the well casing head 7 and the sealing surface 1 of the lower part 101 of the Christmas tree.
It is installed between 01a. A mandrel device 30 is attached to the lower part 101 of the Christmas tree by the interaction of this mounting flange 31 and a retaining ring 32. Mandrel 3 rivers Christmas tree bottom 10
It is inserted into the recess 30a provided in 1. retaining ring,
That is, the retainer 32 is slid from the lower part of the mandrel 30 and attached to the lower part 101 by means of mounting bolts 33, thus locking the mandrel to the lower part 101. The fluid seal between the lower part 101 and the mandrel 30 is provided by a conventional sealing element 34 attached to the mandrel 301.
It is carried out by As best seen in FIGS. 2, 3 and 5, the valve arrangement 50 is connected to the well casing.
They are installed in the head 7 at approximately the same position D.

More specifically, the valve device 50 is located in an annular area 51 formed between the outer surface of the mandrel 30 and the inner surface of the well casing 8. The well casing 8 is supported in substantially the same D alignment within the well casing head 7 by screw means generally indicated at 107. Therefore, the well casing head 7 also functions as a hanger for the well casing 8. Also, as shown in FIG. 2, a seal bag 19 provides a fluid tight seal between the well casing 8 and the well casing head 7. Well casing 8 has a total of 2
An alignment member 20 is attached by a screw connection shown at 1, 21a, and this alignment member is held by a biasing spring 24.
The second alignment member 22 is connected to a substantially link-shaped shim block 2.
I'm pushing him to match up with 3. As best seen in FIG. 3, these matching villages 20 and 22 are
It is provided with inner guide surfaces 20a and 22a, and these guide surfaces absorb the seating work odor (not shown) from the well casing 8.
It functions as a ``funnel'' that guides you to align correctly. The valve holder 50 is retained within the well casing 8 by a retaining ring 59.

The retaining ring is attached to the well casing by six retaining screws, as best seen in FIGS. Valve device 50, thus located approximately concentrically within the casing head, will receive mandrel 30 as the Christmas tree is lowered onto the well casing head. As shown in FIGS. 3 and 5, the shape of the mandrel 30 is substantially tubular.

The unobstructed center hole 13 of the mandrel 30 serves as a path for a tool (not shown) in the seabed hole. tubular mandrel 3
Internal hydraulic pressure pipe sections 37a and 37b are integrally formed within the wall section 40 of 0. These hydraulic conduits direct working fluid through the mandrel. The working fluid is supplied through conduits 35a and 3 which lead to hydraulic channels 135a and 135b, respectively, provided in the lower part 101 of the Christmas tree.
5b from the insulating block 9 to the inner hydraulic conduit section 37.
Porridge is fed to a and 37b. Annular inlet area 36a, 36
b are provided, and hydraulic channels 135a, 135b are provided.
This solves the problem caused by misalignment between the hydraulic pressure pipes 37a and 37b. Since the annular inlet areas 36a, 36b are similar in shape, for the sake of brevity, inlet area 36a, 36b is similar in shape.
I will only explain about. The inlet area 36a is defined by a combination of an inner annular recess 38a formed in the surface of the recess for receiving the mandrel 30 and an annular recess 39a formed in the outer surface of the mandrel 30. These recessed portions 38a and 39a allow the mandrel 30 to be recessed 30
When installed inside a, they align with each other.
Additionally, as best seen in FIG.
3, 36b are separated by a sealing element 34;
Working fluid is prevented from leaking out of these areas and causing a loss of working pressure in the hydraulic line. Inner hydraulic pipe connection part 37
The ends of a, 37b are respectively annular exit areas 42a, 4
2b, and these outlet areas are connected to the valve arrangement 5 at 53a and 53b, as best seen in FIG.
Occurs when 0 is released.

An unobstructed flow path is thus provided from the insulating valve block 9 through the mandrel 30 to the annular inlet areas 36a, 36b and to the annular outlet areas 42a, 42M.
Turning again to the interaction of the mandrel 30 and the valve assembly 50, the abutment shoulder 41 of the mandrel 30 is seated in the valve assembly 50 and the well head connector assembly 6 is attached to the well casing head 7. This valve device 50 is pushed to the open position when the valve is opened.

The guard shoulder portion 41 is integrally formed on the outer surface of the mandrel 30. As previously mentioned, the valve pupil 50 is located approximately concentrically within the well casing head 7 so that when the well head connector assembly 6 is installed in the well casing head 7, Receive 30.

The valve bag hawk 50 is connected to the hydraulic pressure pipes 37a and 3 in the mandrel 30.
7b. These hydraulic pressure pipes are connected to hydraulic pressure pipe sections 47a and 47b in the well casing 8, respectively. The valve device 50 has a generally tubular body which is slidable longitudinally within an annular region 51 formed between the mandrel 30 and the well casing 8.

A valve boat is provided which consists of internal hydraulic conduit portions 55a, 55b integrally formed in the wall of the body of the valve 50. These inner hydraulic conduit portions 55a, 55b align with the mandrel's annular outlet sections 42a, 42b, respectively, when the mandrel 30 is fully seated within the valve arrangement 50. At this time, the inner hydraulic pipe sections 55a and 55b receive the working fluid from the mandrel 30, and the well casing 8
The working fluid is introduced into outlet recesses 63a, 63b which extend through the hydraulic pressure pipes 47a, 47b provided in the.
A mandrel seat 52 formed on the inner surface of the tubular body of the valve device 50 is adapted to receive the abutment shoulder 41 of the mandrel 30.

During regular boring operations, the Christmas tree 1 is attached to the well casing head 7 by the well head connector assembly 6, and the shingle shoulder 41 of the mandrel 30 is connected to the mandrel seat 52 of the valve arrangement 50. is fully seated.

The valve device 50 is pushed into the open position as shown in FIGS. 3 and 4, and the hydraulic line 35 from the insulating valve block 9 is
a, 35b are connected to the hydraulic pipe connections 47a, 47b of the well casing 8 through the mandrel 30 and the valve device 50. With the valve 50 in such an open condition, sub-bottom hydraulically actuated devices, such as leak prevention devices, are actuated by the actuation pressure through these conduits. A biasing device is provided in conjunction with the valve assembly 50 to urge the valve assembly into the closed position when the mandrel 30 is withdrawn from the valve assembly as best seen in FIGS. Automatically seals hydraulic lines. In the illustrated embodiment, a plurality of offset springs 58 are disposed circumferentially around the lower end of the valve device 50 and are received by a spring seat 56 formed integrally with the valve device 50. Well casing 8
An abutment portion 57 is formed in the inner bore approximately perpendicular to its axis, which positions the biasing spring 58 relative to the spring seat 56 so that the biasing spring 58 is abutted. Part 5
7, these springs apply a biasing force to push the spring seat 56 and the abutting portion 57 away from each other. Thus, when the mandrel 30 is fully seated in the valve assembly 50 and the valve assembly 50 is in the open position, the biasing spring 58 is compressed to increase the biasing force on the valve assembly 50. For example, when the mandrel 30 is pulled out of the valve assembly 50, such as when the well head connector assembly 6 and Christmas tree 1 are separated from the well casing head 7 (FIG. 5), the offset Spring 58 is spring seat 5
6 and the valve device 50 are pressed away from the abutting portion 57.

This means that the valve device 50 is connected to the inner hole of the well casing 8.
In particular, as shown in FIG.
48b faces the outer wall portion of the benbishi straight 50. Therefore, the inlet boats 48a and 48b are blocked, and the conduit 4
7a, 47b to prevent the working fluid from leaking into the sea. As can be seen from FIGS. 2, 3, 5, and 6, the hydraulic line sections 47a, 47b are sealed from the surrounding environment, but the valve device 50 is equipped with a shunt device 149. This partial arrangement interconnects the annular recesses 49a, 49b on the outer surface of the valve device 50.

As best seen in Figures 5 and 6, the annular depression 4
9a and 49b, when the valve device 50 is in the closed position,
They are aligned with the hydraulic pipe sections 47a and 47b, respectively. Therefore, these hydraulic conduit sections can work together to close the submarine hole leakage prevention device when the mandrel 30 is removed from the valve device 50. Referring to the leak prevention device as an example for purposes of explanation only, in operation, the leak prevention device includes hydraulic conduit portions 47a,
47b (separately controlled) to two sources of pressurized working fluid.

The two sources of pressurized hydraulic fluid actuate the leak prevention device into open and closed positions. For safety purposes, mechanical means are provided to automatically close this side of the leak-prevention ring unless the operating pressure on the opening side overcomes the mechanical biasing means. The improved valve device 50 of the invention has a hydraulic pipe section 47a.
, 47b is equalized through the separation device 149;
The mechanical biasing means of the downhole leakage prevention device thereby automatically closes the device.

In this way, the valve device of the present invention provides the hydraulic pipe section 47a.
, 47b from the underwater environment, and at the same time equalizes the pressure between the pipe sections and closes the leakage prevention device.

Both of these leakage prevention effects are effective in preventing environmental pollution due to accidental accidents during boring operations, which are carried out under extremely difficult conditions and are extremely susceptible to natural forces.
44,5 to provide a fluid tight seal between the mandrel 30 and the valve arrangement 50 and between the valve arrangement and the well casing 8.
Sealing means, indicated generally at 4, are provided. To specifically consider the seal between the mandrel 30 and the valve arrangement 50, referring to FIGS. 3 and 4, a resilient compressible sealing member 44 is mounted around the mandrel 30 and aligned longitudinally. The annular outlet sections 42a, 42b are separated from each other and also prevent leakage of working fluid between the mandrel 30 and the valve arrangement 50.

A seal member 54 similar to seal member 44 provides a fluid-tight seal between valve arrangement 50 and well casing 8;
This is installed in a circumferential recess provided in the outer wall surface of the valve device 50.

The seal member 54 is located longitudinally relative to the valve assembly 50 to prevent liquid leakage, whether the valve assembly 50 is in the open position as shown in FIG. 4 or in the closed position as shown in FIG. Fluid sealing is performed on both sides of the inlet boats 48a and 48b with respect to the pressure pipe fittings 47a and 47b.

[Brief explanation of drawings]

Figure 1 shows the boring template and the Christmas tree on the well casing head;
FIG. 2 is a cross-sectional view showing the mandrel pedestal of the present invention attached to the valve device and well head connector assembly of the present invention within the well casing; FIGS. 3 and 4 are cross-sectional views of the well head; Detailed cross-sectional view showing the valve assembly held in the open position by the mandrel when the connector assembly is installed in the well casing; Figure 5 shows the mandrel removed from the valve assembly and pushed into the closed position by the biasing means FIG. 6 is a detailed sectional view showing the interaction of the biasing means and the valve arrangement and the sealing means between the valve arrangement and the well casing. 1...Christmas tree, 2...information post, 3...
...Guiding cable, 4...Guiding structure, 5...
...Bowling Template, 8...Well Head
Connector assembly, 7...well casing
Head, 9...Insulation valve block, 30...
...Mandrel, 50...Valve device.ノZ--Z- 持ゞ・ 2. Tsutomu・5・NoZ foot・6・

Claims (1)

[Scope of Claims] 1. A safety device for controlling the flow of fluid through a hydraulic pipeline in a subsea well casing in response to attachment and detachment of a well head connector, which is attached to a well head connector assembly. and a mandrel device that enters the well casing head upon seating of the connector assembly or well casing head, and movably mounted within the casing head in the path of the mandrel device; A safety device comprising a valve device actuated by the mandrel device in response to attachment and detachment of the connector from the casing head to control fluid flow through the corresponding hydraulic line. 2. The safety device according to claim 1, which is combined with the valve device and presses it to a closed position, and when the mandrel device is removed from the valve device, the hydraulic pipe line is closed. A safety device characterized in that it includes biasing means for sealing. 3. The safety device of claim 1, including means for mounting said valve arrangement substantially concentrically within said casing head, and wherein said well head connector assembly is mounted on said well casing head. A safety device characterized in that, when installed, said valve device is pushed into an open position by said mandrel device. 4. The safety device according to claim 1, wherein the mandrel device and the valve device are provided with working fluid passages, and when the mandrel is actuated to the open position of the valve device, the passages are mutually connected. A safety device characterized by being in communication with. 5. The safety device according to claim 1, wherein the safety device is incorporated in the valve device, and the working fluid passageway/pipe line is connected between the mandrel and the valve device and between the valve device and the well casing. 1. A safety device comprising a sealing means for providing a fluid-tight seal against the device. 6. The safety device of claim 1, wherein the mandrel device includes a generally tubular body portion and an inner hydraulic conduit portion for conducting a working fluid through the mandrel device.
and an abutment shoulder seated on the valve assembly and urging the valve assembly into an open position when the well head connector assembly is installed in the casing head. Device. 7. The safety device of claim 1, wherein the valve device includes a generally tubular body portion longitudinally slidable within an annular region between the mandrel device and the casing head; a valve port device aligned with an outlet portion of the inner hydraulic conduit of the mandrel to receive working fluid from the mandrel device and direct it through the valve device when the device is fully seated within the valve device; A safety device characterized by comprising: 8. In the safety device according to claim 7, when the mandrel device is removed from within the valve device and the valve device is pushed to the closed position by the biasing device, an annular recess formed in the outer surface of the valve device to align with a hydraulic conduit in the well casing; and an annular recess integrally formed in a wall of the tubular valve body to interconnect the annular recess. an inner shunt device;
Thereby, the annular recess and shunt device interconnect the hydraulic conduits when the mandrel device is disengaged from the valve device and the valve device is pushed into the closed position by the biasing device. A safety device characterized by equalizing the pressure between them. 9. In the safety device according to claim 2, the biasing means includes a spring seat formed integrally with the valve device and receiving the biasing spring means, and an inner hole of the well casing, The spring seat includes an abutting portion provided substantially perpendicular to the axis of the spring seat, and a biasing spring means disposed between the spring seat and the abutting portion to press them substantially away from each other. safety equipment. 10 A method for automatically sealing hydraulic lines in a subsea well casing when it is disconnected from a corresponding well head connector, the method comprising attaching a mandrel to the well head connector assembly. a valve device is installed in the well casing head so as to be movable in open and closed positions with respect to the working fluid conduit of the well casing head, and the well head connector assembly is attached to the well casing head. the mandrel and valve assembly to the open position by engaging the mandrel and the valve assembly when the mandrel and the valve assembly are disengaged by disengagement of the connector from the well casing; A method consisting of moving the valve arrangement into the closed position by its own biasing force.